1. Field of the Invention
This invention is directed to an active air cleaning controller for an HVAC system.
2. Background of the Invention
A typical forced-air heating, ventilation and air conditioning (HVAC) system may have a series of ducts that collect air from a living environment and that supply the collected air to an air cleaner, a blower, and a heating unit and/or cooling unit before distributing the conditioned air back to the living environment. In HVAC systems that use an air cleaner, the air cleaner removes particles and/or contaminants from the air. This can improve the quality of the air for people in the living environment serviced by the HVAC system.
In many cases, cleaned air provides substantial advantages for the people in the living environment serviced by the HVAC system. If, for example, the HVAC system services a house inhabited by one or more persons with pollen allergies, the HVAC system may employ an air cleaner that is particularly effective at removing pollen from the air. If the HVAC system is being supplied in part or in whole by air from the outside environment, removing pollen from the air before injecting the air into the living environment is clearly advantageous.
Typically, HVAC systems are designed to provide or circulate air that has been conditioned for a certain temperature range. When a thermostat determines that the temperature of the air in the living environment has fallen or risen outside of a desired temperature range, the thermostat outputs a call signal to a controller of the HVAC system to request that the HVAC system provide air to the living environment that has been heated or cooled to raise or lower the temperature of the living environment, respectively. To do so, the HVAC system will pull in air either from the living environment and/or from outside the environment and heat or cool that air as needed. If the HVAC has an air cleaner in line with the air return ducts, the air that is being heated or cooled will also have passed through the air cleaner and been cleaned.